Photosensitizer-complexed polypyrrole nanoparticles for activatable fluorescence imaging and photodynamic therapy.

Here, we propose the use of photosensitizer-complexed polypyrrole nanoparticles (PCe4@HANP) as activatable theranostics. The fluorescence emission and singlet oxygen generation of PCe4@HANP were mostly turned off in the extracellular region, but became highly fluorescent and phototoxic upon internalization into cancer cells, enabling real-time near-infrared fluorescence imaging and photodynamic therapy of cancer.